In the microelectronics industry, integrated circuits (ICs) may be formed on a semiconductor die. The die may then be packaged and sold. Typically, the die may be flip-chip connected to a substrate which may provide electrical connection to a printed circuit board or motherboard. In a standard configuration, an inductor may be provided as a discrete component on the substrate. In other configurations, an inductor may be embedded in the substrate, as is illustrated in FIG. 1.
FIG. 1 illustrates an apparatus 100 including a die 110 connected by interconnects 120 to a substrate 130 having connections 140. Apparatus 100 also includes an underfill material 160 and an inductor 150. Underfill material 160 may completely surround interconnects 120 and may provide protection for die 110. Inductor 150 may be embedded in substrate 130.
Inductor 150 may provide various functions, such as energy storage, selective channel frequency, filtering, and noise reduction for die 110. In general, the performance of an inductor may improve with increased Q factor (inductor reactance over resistance), reduced resistance (R), reduced stray capacitance (C) and reduced loop inductance. Compared to an inductor mounted on substrate 130, an embedded inductor may have the advantage of providing less loop inductance. Limitations in the performance of an inductor may limit the circuit applications of the IC.
Interconnects 120 may provide electrical connection between die 110 and substrate 130. In general, it may be desirable that interconnects 120 provide minimal mechanical stress between substrate 130 and die 110.